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From: "Michał Pecio" <michal.pecio@gmail.com>
To: bugzilla-daemon@kernel.org
Cc: linux-usb@vger.kernel.org,
	Niklas Neronin <niklas.neronin@linux.intel.com>,
	Mathias Nyman <mathias.nyman@linux.intel.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Subject: Re: [Bug 219039] New: kernel 6.6.39 freezes with QNAP DL-D800C usb case
Date: Sun, 14 Jul 2024 16:03:04 +0200	[thread overview]
Message-ID: <20240714160304.5a6390ec@foxbook> (raw)
In-Reply-To: <bug-219039-208809@https.bugzilla.kernel.org/>

Hi,

Good job finding the bad commit. I'm almost sure that I know what the
problem is - it appears that this commit effectively disables
incremeting event ring pointer under certain conditions, which causes
the IRQ handler to process the same event again and again and never
progress to the next one.

I would try changing the

    return 0;

added by the bad commit into

    inc_deq(xhci, ir->event_ring);
    return 0;

and see if this helps.


Other than that, the commit appears to be valid fix to a real problem
that may happen on isochronous endpoints when MISSED_SERVICE_ERROR is
immediately followed by STOPPED_LENGTH_INVALID, which I think could
occur. The over/underrun conditions are perhaps possible too.

Regards,
Michal

  parent reply	other threads:[~2024-07-14 14:03 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-07-14 12:11 [Bug 219039] New: kernel 6.6.39 freezes with QNAP DL-D800C usb case bugzilla-daemon
2024-07-14 12:15 ` [Bug 219039] kernel 6.6.39 freezes with QNAP TL-D800C " bugzilla-daemon
2024-07-14 12:50 ` bugzilla-daemon
2024-07-14 14:03 ` Michał Pecio [this message]
2024-07-14 14:03 ` bugzilla-daemon
2024-07-14 15:50 ` bugzilla-daemon
2024-07-14 16:28 ` bugzilla-daemon
2024-07-14 16:32 ` bugzilla-daemon
2024-07-15 11:53 ` bugzilla-daemon
2024-07-16  7:53 ` bugzilla-daemon

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